Revert "e1000e: Separate signaling for link check/link up"

This reverts commit 19110cfb.
This reverts commit 4110e02e.
This reverts commit d3604515c9eda464a92e8e67aae82dfe07fe3c98.

Commit 19110cfb ("e1000e: Separate signaling for link check/link up")
changed what happens to the link status when there is an error which
happens after "get_link_status = false" in the copper check_for_link
callbacks. Previously, such an error would be ignored and the link
considered up. After that commit, any error implies that the link is down.

Revert commit 19110cfb ("e1000e: Separate signaling for link check/link
up") and its followups. After reverting, the race condition described in
the log of commit 19110cfb is reintroduced. It may still be triggered
by LSC events but this should keep the link down in case the link is
electrically unstable, as discussed. The race may no longer be
triggered by RXO events because commit 4aea7a5c

 ("e1000e: Avoid
receiver overrun interrupt bursts") restored reading icr in the Other
handler.

Link: https://lkml.org/lkml/2018/3/1/789
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>